Texas Register, Volume 15, Number 4, Pages 145-239, January 12, 1990 (open access)

Texas Register, Volume 15, Number 4, Pages 145-239, January 12, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: January 12, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Mass storage for microprocessor farms (open access)

Mass storage for microprocessor farms

Experiments in high energy physics require high density and high speed mass storage. Mass storage is needed for data logging during the online data acquisition, data retrieval and storage during the event reconstruction and data manipulation during the physics analysis. This paper examines the storage and speed requirements at the first two stages of the experiments and suggests a possible starting point to deal with the problem. 3 refs., 3 figs.
Date: January 12, 1990
Creator: Areti, H.
Object Type: Report
System: The UNT Digital Library
Liquid Argon Maximm Convective Heat Flux vs. Liquid Depth (open access)

Liquid Argon Maximm Convective Heat Flux vs. Liquid Depth

In order to help answer questions about the magnitude of heat flux to the liquid argon in a liquid argon calorimeter which could cause boiling (bubbles), calculations estimating the heat flux which can be removed by free convection were made in February, 1988. These calculations are intended to be an estimate of the heat flux above which boiling would occur. No formal writeup was made of these calculations, although the graph dated 3 Feb 88 and revised (adding low-velocity forced convection lines) 19 Feb 88 was presented in several meetings and widely distributed. With this description of the calculations, copies of the original graph and calculations are being added to the D0 Engineering Note files. The liquid argon surface is in equilibrium with argon vapor at a pressure of 1.3 bar, so the surface is at 89.70 K. The liquid is entirely at this surface temperature throughout the bulk of the volume, except locally where it is warmed by a solid surface at a higher temperature than the bulk liquid. This surface temperature is taken to be the boiling temperature of argon at the pressure corresponding to 1.3 bar plus the liquid head; hence it is a function of depth …
Date: January 12, 1990
Creator: Peterson, T.
Object Type: Report
System: The UNT Digital Library
Future microprocessor farms: Offline and online (open access)

Future microprocessor farms: Offline and online

Microprocessor farms have been successfully employed in high energy physics for both offline analysis and online triggers. As the experiments continue to grow in size, so do the demands for processing power. The preliminary indications are that the large collider experiments will require at least a million VAX-11/780 equivalents of processing power for online trigger decisions and offline event reconstruction. This paper examines the current technology trends and projects the processing power that may be expected with the current farm architectures. 3 refs., 6 figs.
Date: January 12, 1990
Creator: Areti, H.
Object Type: Report
System: The UNT Digital Library
Wideband beam patterns from sparse arrays (open access)

Wideband beam patterns from sparse arrays

Transient radiated fields due to impulsively excited apertures and aperture response due to incident impulsive waves has been the subject of considerable research in acoustics over the last decade. This research is also of importance to wideband radar. Medical ultrasound steered phased arrays use transmitted pulses consisting of from 1 to 3 cycles of a damped sinusoid, which is similar to certain radar systems. As will be shown, planar arrays using ultra-wide band pulses may be formed with very sparsely spaced elements. This makes feasible very high resolution, economical, and relatively simple, steered beam phased arrays. The resolution may be increased simply by moving the array elements further apart. Grating lobes due to aliasing are not formed when the elements are sparsely spaced. In a very sparse wide band array, element spacing effects the form, or signal shape in time, rather than the peak amplitude of the sidelobe structure. The number of elements in the aperture determines the peak sidelobe level which, in theory, may be decreased without limit. 13 refs., 7 figs.
Date: January 12, 1990
Creator: Anderson, F. (Anderson (Forrest), Bernalillo, NM (USA)); Fullerton, L. (Time Domain Systems, Huntsville, AL (USA)); Christensen, W. & Kortegaard, B. (Los Alamos National Lab., NM (USA))
Object Type: Article
System: The UNT Digital Library
Performance of a 500 watt Nd:GGG zigzag slab oscillator (open access)

Performance of a 500 watt Nd:GGG zigzag slab oscillator

Realization of practical multi-kilowatt Nd:garnet lasers will require the scale-up of crystal dimensions as well as more powerful pumping sources. A high average power zigzag slab crystal amplifier testing facility has been established at LLNL which employs two 100 kW{sub e} vortex stabilized arc lamps, cooled reflectors and a cooled, spectrally filtered, crystal slab mounting fixture. The operational characteristics of the first crystal laser to be tested in this setup, a Nd:GGG zigzag oscillator, are presented. A Nd:GGG crystal of dimensions 18 {times} 7 {times} 0.5 cm{sup 3}, doped at 2 {times} 10{sup 20} cm{sup {minus}3} Nd{sup 3+} atomic density, was pumped by up to 40 kW of filtered argon line emission. A small-signal single pass gain (losses excluded) of 1.09 was measured with a probe laser when the DC input to the lamps was 43 kW{sub e}. Our power supply was then modified to operate in a pulsed mode and provided one to three milliseconds pulses at 120 Hz. An average optical output power of 490 watts was obtained at a lamp input power of 93 kW{sub e} in an unoptimized resonator. The laser output power declined after a few tens of seconds since the slab tips were not …
Date: January 12, 1990
Creator: Zapata, L.; Manes, K. R.; Christie, D.; Davin, J.; Blink, J.; Penland, J. et al.
Object Type: Article
System: The UNT Digital Library